1. Field of the Invention
The present invention is directed to analog signal receivers and, more particularly, to methods and systems for equalizing (e.g., minimizing distortions within) analog data signals.
2. Background Art
Conventional signal propagation mediums, such as conventional backplane material (e.g., FR4) and conventional wires (e.g., IEEE 1394 “firewire),” are generally suitable for lower data rate signals, up to about 622 megabits per second. At higher frequencies, however, data signals are increasingly subject to frequency band-limiting distortions such as inter-symbol interference.
Inter-symbol interference results, in part, from unsettled response times following signal state changes. In other words, when a first state change does not settle before a second state change, the state changes can begin to overlap and can become more difficult to distinguish from one another.
A conventional approach compensates for inter-symbol interference with pre-emphasis, which boosts signal amplitudes prior to transmission. Pre-emphasis techniques typically require prior knowledge of signal paths. When an integrated circuit (“IC”) is intended to be used in multiple systems, the IC needs to be pre-programmed for various system characterizations. This is costly, time-consuming, and inefficient. Pre-emphasis also typically causes electromagnetic interference problems such as impedance mismatching and other reflective problems.
What is needed is a method and system for minimizing frequency band-limiting distortions, such as inter-symbol interference, in analog data signals. What is also needed is a method and system for adaptively minimizing frequency band-limiting distortions, such as inter-symbol interference, in analog data signals.